by Dr. Lee Vliet
“Viral Hemorrhagic Fever” (VHF) refers to a group of highly infectious severe viral illnesses caused by over 20 different small particle pathogenic RNA viruses in four different viral families. Examples include Yellow fever, Lassa fever, Ebola, Marburg and others listed in the Table at end of our FACT SHEET. These highly infectious viruses lead to a potentially lethal disease syndrome characterized by fever, malaise, vomiting, mucosal and gastrointestinal (GI) bleeding, edema, and hypotension. Clinical and epidemiological data are very limited because outbreaks have been sporadic, few cases, and typically limited primarily to Africa or Asia.
Public Health Threats and Transmission: The hemorrhagic fevers of most serious concern, particularly Marburg and Ebola, are spread through person-to-person contact, including respiratory droplets from people who are actively sick (viremia phase) and are coughing or sneezing. Infected people with symptoms (viremia phase) can spread the virus to uninfected people when the infected person’s secretions (saliva, respiratory droplets, blood, vomit, stool, vaginal secretions, and/or semen) contact mucous membranes (mouth, nose, eyes, rectum, vagina, or breaks in the skin) of someone who is not infected. There is no well-documented evidence of spread during the asymptomatic prodromal phase, as discussed in the article cited below. Family members can be infected as they care for sick relatives. Healthcare personnel can be infected if not using proper protective equipment that covers them from head to toe. Hospitals also use the decontamination strategies described in our FACT SHEET.
For more detailed information on the potential public health threats and spread of these illnesses, see the important 2002 consensus review article “Hemorrhagic Fever Viruses as Biological Weapons: Medical and Public Health Management” from Johns Hopkins School of Public Health Working Group on Civilian Biodefense: https://www.truthforhealth.org/2022/07/hemorrhagic-fever-viruses-as-biological-weapons/